Re: [Qemu-devel] [RFC v3 04/24] linux-user: riscv: Fix compile failure on riscv32 hosts

[Richard Henderson]

On 12/7/18 6:46 PM, Alistair Francis wrote:
> When cross compilling for riscv32 hosts using GCC 8.2 this error is seen:
>     error: '__NR__llseek' undeclared (first use in this function); did you 
> mean '_llseek'?
> 
> To avoid the error let's ensure that __NR__llseek is defined.
> 
> Signed-off-by: Alistair Francis <address@hidden>
> ---
>  linux-user/riscv/target_syscall.h | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/linux-user/riscv/target_syscall.h 
> b/linux-user/riscv/target_syscall.h
> index ee81d8bc88..af73f71839 100644
> --- a/linux-user/riscv/target_syscall.h
> +++ b/linux-user/riscv/target_syscall.h
> @@ -47,6 +47,11 @@ struct target_pt_regs {
>  #endif
>  #define UNAME_MINIMUM_RELEASE "4.15.0"
>  
> +/* This is sometimes needed to compile riscv32 Linux user mode */
> +#if !defined(__NR__llseek) && !defined(__NR_lseek)
> +#define __NR__llseek __NR3264_lseek
> +#endif

I'm not quite sure how this could be.  Upstream I see

#if __BITS_PER_LONG == 64 && !defined(__SYSCALL_COMPAT)
...
#define __NR_lseek __NR3264_lseek
...
#else
...
#define __NR_llseek __NR3264_lseek

so this define should already exist.

Do you have the wrong headers installed for the cross-build?


r~